Colorado Initiative 3 (1980) was an initiated constitutional amendment, regarding annexation by municipalities, on the November 4, 1980 election ballot in Colorado, where it was approved.
| Initiative 3|
| Yes|| 601,302|| 56.7%|
Election Results from: State Legislative Council, Ballot History
Text of measure
Language on the ballot:
|| Shall Article II of the Constitution of the State of Colorado, be amended to provide that an unincorporated area may be annexed to a municipality only if the annexation has been approved by a majority vote of the landowners and the registered electors in such area who vote on the question, or if the annexing municipality has received a petition for annexation signed by persons comprising more than fifty percent of the landowners in such area and owning more than fifty percent of such area, or if such area is entirely surrounded by or is solely owned by the annexing municipality; and providing that this section does not apply to the city and county of Denver entirely surrounded by or is solely owned by the annexing municipality; and providing that this section does not apply to the city and county of Denver to the extent that annexations thereto are governed by other provisions of the state constitution?